Appearing immediately after, also in 2014, was a prediction by Duan at al.[1]} that for a SH\(_3\)  stoichiometry [labeled at the time after the initial constituents, (H\(_2\) S)\(_2\) H\(_2\) ), and later as H\(_3\) S], a high symmetry, atomic H structure was predicted to be the most stable one in the 150-200 GPa range, and the calculated T\(_c\)  peaked just above 200K in the 160-200 GPa region. Coupling strength \(\lambda \) =2.2 was calculated, with 25% arising from the low energy S modes. The cubic structure has one of the highest symmetries possible for this stoichiometry: SH\(_6\)  octahedra are connected by H atoms which are coordinated only with two S atoms, see Fig. REF (a). Such a remarkably high prediction must have seemed to most readers as beyond comprehension, yet it was based on successful structure search algorithms and the established DFT-ME theory. Theoretical study of sulfur hydrides was confirmed and extended in 2015 by Akashi et al.[2]} and Errea et al.,[3]} which promoted the understanding of the relation of electronic structure and microscopic processes to promote high T\(_c\) .
